Strap dispenser



D c- 1964 J. w. CULPEPPER ETAL 3,162,394

STRAP DISPENSER Filed May 7, 1963 mmvron JOHN w. CULPEPPER BY EDWARD J. STAHNKE ALVIN L. WINKLER United States Fatent Ofitice 3,162,394 Patented Dec. 22, 1964 3,162,394 STRAP DISPENSER John W. Culpepper, 3 La Fayette Drive, Jericho VL, and

Edward J. Stahnke and Alvin L. Winkler, Chicago, BL; said Stahnke and said Winkler assignors to Acme Steel Company, Chicago, 'IlL, a corporation of Illinois Filed May 7, 1963, Ser. No. 278,658 Claims. (Cl. 242-185} The present invention relates to the dispensing arts, and more particularly to a new .and improved machine and mechanism for dispensing strapping and like materials from coils thereof.

It has been common practice in the past to mount or support a coil of strapping material on a rotatable frame or reel and to rotate the reel, either manually or by power, in order to turn the coil and thereby feed the material therefrom. The prior utilization of this simple practice with unsophisticated mechanisms has been adequate for many purposes, but certain problems, not heretofore entirely satisfactorily or inexpensively solved, have often been encountered, particularly where the coils of material being dispensed are relatively heavy, the desired feeding of the material is intermittent or at varying rates, and where the material being dispensed is resilient and therefore difficult to command and control. In the dispensing of metal strapping, for example, all of these conditions are usually present. The coils of metal strapping are relatively heavy and their rotation cannot ordinarily be stopped instantly when the need for additional strapping ceases. Neither is it easy instantly to change the rate of rotation of the metal coil in response to a reduction in the rate at which the strapping is used. As a result, over-run of the coil is often encountered and a slack or untensioncd length of strapping is released from the coil. This has heretofore been particularly troublesome in the dispensing of steel strapping and the like, for the strapping is often quite resilient and is usually wound in coils having a radius of curvature substantially less than that of the so-call'ed coil-set or bundle curve (residual curvature), if any, of the strapping. As a result, untensioned or slack lengths of such metal strapping outside the confines of the coil tend quickly to get out of control, and buckling and tangles often result. This leads to losses in operating time and possible damage to some of the strapping. In addition, occasions have been encountered in the past wherein loose and uncontrolled c'onvolutions of strapping have sprung out of a coil, much in the fashion that might be expected of a clock spring, when slack has developed in that uncontrolled portion of strapping which has just been withdrawn from the coil.

One of the principal objects of the present invention is to solve the foregoing problems by providing, in mech anism for dispensing strapping or the like, relatively simple and very inexpensive apparatus which automatically assumes control of the slack or untensioned strapping by gripping the same in response to the tendency of the strapping to buckle. Another object of the invention is to provide such apparatus wherein a controlled buckling of the strapping is intentionally permitted to occur to take up any slack that arises in the strapping and wherein the buckling force of the strapping is itself used to generate the gripping force for controlling the strapping. Still another object of the invention is to provide such apparatus wherein the strap gripping force is progres sively and automatically increased as the slack absorbing buckling increases, so that the control automatically becomes more forceful and positive as the need therefor increases.

Yet another object of the present invention is to provide simple and inexpensive apparatus of the kind referred to above, wherein the strap gripping and control mechanism exerts a braking action on. the longitudinal movement of the strapping, and wherein this braking action is generated by the bucklingv forces and automatically is increased as the buckling and needfor braking, action increases. Still another objectis to provide in such apparatus means whereby the gripping and braking mech anism is utilized to control power means for driving the coil from which the strapping or like. material is being dispensed. Another object is to provide, in combination with the. foregoing apparatus, an improved drive means for the coil. and means by which said gripping and braking apparatus. may be easily retractedfrom an obstructing position when. a fresh coil. is about to be placed in position for dispensing, and wherein the retraction of said apparatus automatically renders inactive the drive means for the coil.

These andother objects and advantages of the present invention will be apparent from the following'descripti'on of a preferred embodiment thereof, taken with the accompanying drawing, wherein:

FIG. 1 is a top planview of a strap dispenser constructed in accordance with the invention, a sensor unit being shown bothin full lines and in broken lines to represent the movement thereof between different positions, and the discharge path for the, strapping being shown by broken. lines corresponding to the positions of the sensor unit;

FIG. 2 is an elevational view of the mechanism of FIG. 1, with certain portions of the mechanism being broken away substantially along the line 22'in.FIG. 1;

FIG. 3 is a perspective view of the apparatus showing the general mode of its operation, with, certain details of the apparatus being omitted'forsimplicity of illustration; and

FIG. 4 is a greatly enlargedfragmentary cross-sectional view taken substantially along a horizontal plane passing through a loop provided onthe outer end of the sensor unit, with the path of the strap through the loop being shown schematically in solid lines to represent the disposition ofthe strap with respect to the arms of the loop when the sensor unit is in the solid-line position illustrated in FIG. 1', and with the disposition of thestrapping with respect to the-loop being shown in broken lines to represent the relative position of the strapping with respect to the loop when'the sensor unit is in the brokenline position thereof illustrated in FIG. 1.

As shown in the drawing, the apparatus includes a housing 10' of sheet metal or the like having a bottom wall 11, a front wall 12 which slopes-diagonally upwardly from the front edge ofthe' bottom wall 11, and a top wall- 13- whichmay join the upper-edge portion of the front wall 12 in a gradual curve, the casing or housing it) being provided with opposite end walls 14 and 15. The apparatus also includes a rigid base frame which is comprised, in part, of a pair of frame members 16 and 17, each of which may be fabricated from channel iron or the like of U-shapedcross section. The two frame members 16 and 17 are secured in any suitable manner, as by welding or the like, upon the upper side of the bot- I tom wall 11 of the housing 10, and the two frame members extend rearwardly from the open rear portion of the casing lit and thereupon converge toward each other, as illustrated in FiG. 1. The converging ends of the frame members 16 and 17 are joined, as by Welding or the like, by a further frame member 18 which may comprise a bar bent adjacent its middle. As seen in FIG. 1, the bent middle portion of the bar 18 is joined to the outermost converging ends of the frame members 16 and 17, so that the remaining portions of the bar 18 provide radially-extending base supports. The lower-edge p'or tions of the frame members =16, 1-7 and 18, as well as tion of the frame vmembers 16, 17 and 18 for rotation' in a coil-unwindingdirection about a vertical axis. In the particular apparatus illustrated, an upstanding shaft 19 is welded or otherwise secured at its lower end to the converging ends of the frame members 16 and 17,

in the position best seen in FIGS. 1 and 2., A collar 2t} is fixed.to this shaft above the frame members 16, 17 and 18, and a hub. of any suitable construction is rotatably mounted upon the shaft 19 above the collar 20. In the particular form of the apparatus illustrated in FIG. 2, this hub is comprisedof a pair of commercially-available casings or housings 2'1 and 22 containing ball bear: ings and suitable races, so that the housing 21 and 22 will rotate freely-with respect to the shaft 19 and about its axis. If desired, the housings 21v and 22 and the ballbearing mechanisms contained therein may be such that the bearing assemblywithin the casing 21 may rotatably rest upon the upper side of the collar 20. The beare ing mechanism within the casing 22 may correspond to. that employed within the casing 21, and an, upper collar 23 may be secured to the shaft 19 .above the casing 22 and its bearing mechanism, so that the latter may notbe moved axially upwardly along the shaft 19.

. In the form of the apparatus illustrated in FIG. 2, th

bearing casings 21 and 22 arev respectively provided with outwardly-extending flanges 24 and 25, which .are fixed upon the casings. A plurality of bolts 26, provided with a 7 suitable washers if desired, are'passed through appropriate openings in the flanges 24and 25, and a pair of annular clamping plates 27. and 28 are mounted on these bolts between the flanges 24 and 25.

A plurality of radially-extending supporting. arms 29,

of inverted U-shaped cross section, are mounted at their: inner ends between the clamp plates 27 and28 -.jj For this purpose, the inner ends of the arms, 29 are provided with stubs 30 which are disposed between the two plates 27 and 28. the upper wall of each supporting arm 29-and through A bolt-31 is passed downwardly through the two clamp plates 27 and 28.,it being understood that,

when the inuts provided on the bolts are tightened, the two clamp plates are respectively drawn tightly against the upper and lower edges ofthe stub portion 30 of each arm 29, thereby to retain each arm in a rigid radially-' directed position'with respect to the clamp plates 27 and 28 and with respect tothe. flanges 24 and 25 provided on thecasings21 and 22 of'thehub assembly. The outmay exist; I 3 Electric energy cable 50 connected to a power source, not shown, and the to cover the hub portions of the coil-supporting wheel assembly and the clamping bolts 31 which secure the inner ends of the arms 29 between the clamp plates 27 and 28. This bell-like cap 35 is closed at 'itsupper end by a wall 36, as best seen in FIG. 2, and the bell-like cap is secured in position bya screw 37 which-extends sides of the motor with coaxial .pinions 43 which are ro-- tatably journaled in the upstanding legs of another yoke 44 which may be secured in any suitable fashion, such as by welding or the like, upon the upper surface of the wall 11, within the housing 10. Itwill. be observed. that the yoke 42 and the pinions42a are disposed adjacent-the drive end of the motor 40, so that the motor willpivot about the axes of the pinions 43, with the weight of the body of themotor tending always to urge the motor to be pivoted in the direction of the arrow 45 in FIG. 2. The drive shaft of the motor is provided with a drivewheel 46 of rubber or the like which is disposed directly beneath the flange 32a of the rim'32 and in driving contact therewith. Thus, the weight .of themotor and its tendency constantly to be pivoted in the direction of the arrow causesthe periphery of the drive Wheel 46 to bear 'constantly upon the drive surface on the underside of the flange 32a of the.rim 32. It willalso be observed that .the pivotal'mounting ofthemotor 40 will cause the drive or maynot lie precisely in a plane thatis horizontal or is normal to the axis of the shaft 19. Thus, the pivotal mounting of the motor and the drive arrangement just described allows for wide constructional tolerances andprovides constant drive force despiteany irregularities that for'the-motor40 may bepr ovided by a cabl'e,if. desired, maybe of the disconnect type which ,may be plugged into any suitable electric receptacle 50a carried by the wall.14 of the housing 10. I The electric er-end portionsof the supporting arms 29 are undercuu and these undercutportions have secured thereto a cir' cular rim 3-2 of inverted L-shaped cross section, the rim 32 thus being provided with a.horizontally projecting an-.

nular flange 32a and a downwardly extending flange 32b both of which flangesrnay be secured, as by welding or the like, withinthe undercut portions at the outer endsfl j,v

of the respective supporting arms 29.

The under surface of the flange 32a of .the' r1m;;32

' serves as a frictional drive surface for the coil-supporting wheel assembly, as willbe later explained herein.

Upstanding stub arms 3.3,' which may also beiof U- shaped cross section, "if -desired, are welded or otherwise secured to the upper surfaces of thejrespective support arms 29 adjacent their outer ends, as bestseen inFI GS.

' l and 2.1'The coil 'ofistrappingi34 to be unwound is repr s y broken hues" FIG and It W111 e {"10056 rivets or t-hehke, upon the upstandingears 61 of I 1. t t s'd 'u on the a v v 1 I served that thls c011 Sunny fess on 1 s e p 'I the bracket'60. The. bracketassem'bly 62f'thus provides upstanding stub arms 33 serving to lHSUI'Q'lIhatIh6 coil'is not displaeed from its position on thefsupporting A generally cylindrical bell-like cap 35,; open at .lilS, bottom ,end, rests in-invertedpositionupon the. upper surfaces of the-radially extendinga'support arms.29, so asi switch 53 is. closed.

leads from the cable are shown schematically in FIG. 1 and extend through the wall 14 ofthehousing 10. One

' of the leads 51 may extend directlyto one of: the terminals of-the motor '40. The, other lead 52' extends to one side of a normally open, plunger type commercially available micro switch 53 whichrnay be mounted, as by screws 54, uponthe underside of the upper wall 13 of the housing '10; 'Another electrical lead 5223 extends from the other side of the-normally open switch'53 to. the other terminal .of thernotor 40, so that the motor 40 will operate and will opposite ends, is secured, as by welding or; the like, upon theupper surface of the upper Wall 13 of the housing 10.

V A second bracket assembly 62 having at its oppositeends depending ears 63 'which arepivotally mounted, as by an upperwall 64 which extends between the cars 63, and a lower wall 65 also extends between the ears 63, 'the lower wall 65 being secured in any suitable ,way between theears 63 infixed, spaced position 'withpresp'e'ct to the 'wall 64-and'di rectly,therebeneath; LA base block 66 of a 'sensorjunity'iis pivotally mounted between the upper rod length 67d is closed by another rod length 67e.

1 and lower walls 64 and 65 of the bracket assembly 62 by means of a vertically disposed pin 68 which is fixed to the block 66 and the opposite ends of which are journaled in the walls 64 and 65 for free rotation therein. The lower end of the pin 68, when the bracket 62 is in its normal, full-line position shown in FIG. 2, extends downwardly through a rearwardly opening slot provided in the upper wall 13 of the housing 10, the lowermost end of the pin 68 having a cam block 69 fixed thereon. One end of this cam block 69 is provided with a cam surface 70 which is adapted to engage a roller 71 provided on the outer end of a leaf-type actuator 72, of an ordinary commercial type, fixed upon the switch 53 in a well-known manner, it being understood that, when the cam block 69 is rotated to engage the roller 71 and deflect the actuator leaf 72, the switch 53 will be closed to cause the motor 40 to be energized and rotatably drive the coil-supporting wheel assembly previously described.

The sensor unit 67 is preferably of light weight but sturdy wire or rod construction. An arm 67a of the sensor unit is fixed at its inner end in the pivotally mounted base block 66, and the arm 67a extends outwardly as shown in FIGS. 1, 2 and 3, the outermost end of the arm 67a being formed to provide a loop comprising a pair of vertically oriented, parallel, spaced apart rod lengths 67b and 670 joined at their lower ends by a rod length 67d. It will also be observed in FIG. 2 that the upper portion of the loop provided by the rod lengths 67b and 67a and the In the preferred construction, the arm 67a and the elements of the loop are of the very inexpensive unitary construction illustrated in the drawing.

Due to the fact that the depending ears 63 of the bracket assembly 62 are pivotally mounted upon the upstanding ears 61 of the bracket 60, it will be appreciated that the entire bracket assembly 62, with the base block 66 and the cam block 69, as well as the entire sensor unit 67, may be pivoted upwardly in the direction of the arrow 70 to the broken line position illustrated in FIG. 2. Thus, the sensor unit 67 may be elevated and retracted from the area above the coil-supporting wheel assembly when a fresh coil 34 of strapping is being placed upon the coil-supporting wheel assembly. This will avoid any damage to the sensor unit 67 during the loading of the apparatus with a fresh coil of strapping, and it will be appreciated that the retraction or elevation of the bracket assembly 62 from its full-line position in FIG. 2 to its broken-line position, will carry the cam block 69 to a position remote from the switch actuator 72, thereby avoiding any inadvertent energization of the drive motor 40 during the loading of the apparatus.

In the unwinding of the strapping from a coil with the use of the apparatus of the present invention, the strapping is normally unwound from the inside of the coil 34, as best illustrated in FIG. 3. The strapping, being unwound from the coil, passes through a curved discharge path leading toward a discharge guide tube 86 which is secured by a pin 31 or the like upon the underside of the upper wall 64 of the bracket assembly 62. The strapping Passes through the guide tube 80, and this guide, if desired, may be in the form of a helical spring, as illustrated in the drawings. It will be observed that the vertical walls 1 the outer end of the sensor arm 67a;

In loading the apparatus with a fresh coil of strapping, the entire bracket assembly 612 and the sensor unit 67, together with their related parts, are pivoted upwardly to the broken-line position illustrated in FIG. 2, as previously mentioned. The fresh coil of strapping is then laidon its side on the upper surfaces .of the arms 29 in the position indicated by the solid lines in FIG. 3 and by the broken lines in FIG. 2. The bracket assembly 62 and the sensor unit 67 are then lowered to the full line .position shown in FIG. 2. During the loading, it is, of course desirable that the manually operated switch, previously referred to but not shown in .the drawing, be maintained in the off position so that the motor will vnot be energized inadvertently when the sensor unit 67 is lowered to its full line position.

With the elements in the condition just described, a length of the free end of the strapping is uncoiled from the inside of the coil 34, and this free end portion of the strapping is manually threaded through the loop provided on the outer end of the sensor unit 67, care being taken to insure that the strapping is passed on the inside of the rod length 67c and on the outside of the rod length 67b, as illustrated in FIG. 4. The free end of the strapping is then threaded through the exit guide tube 80, thus providing a length of the strapping outside the confines of the present apparatus, which length may be gripped manually and later pulled or may be fed into a strapping machine or other device which utilizes or consumes strapping. As a last step in the loading, sufficient strapping should be withdrawn from the coil 34 to insure that the strapping lies substantially along the discharge path 34b, as shown in FIG. 1, so that the motor 40 will not be prematurely energized. Finally, if a manually operated switch is employed, as previously described, it should be moved to the on position.

In the preferred form of the apparatus, a headed screw 66a (shown only in FIG. 1) is threaded into one side of the pivoted base 65 of the sensor unit 67 in order adjust-ably to limit the outermost pivotal limit of the sensor unit, the head of the screw 66a being adapted to bump the inside surface of the car 63 of the bracket assembly .62.

It will be observed that, after the strapping has been loaded in the manner just described, a pull on the outermost end of thestrapplng, whether the pull is appled manually or by another machine, will cause the sensor unit 67 to pivot from the full line position shown in FIG. 1 toward and into the broken line position of the sensor unit illustrated in FIG. 1. The pivotation of the sensor unit toward or into the broken line position seen in FIG. 1 will cause the cam surface 70 on the cam block 69 to engage the wheel '71 of the switch actuator 72, thereby depressing the switch actuator and electrically closing the switch 53. This will energize the motor 49 and cause the drive wheel 46 thereon to drive the coil-supporting wheel assembly by means of the frictional contact of the wheel 46 upon the under surface of the flange 32a, of the rim 32.

This driven rotation of the coil-supporting wheel assembly will rotate the coil 34 in the coil unwinding direct-ion and thus will feed strapping from the coil through the loop on the outer end of the sensor unit and through the exit guide tube 80. During this driving and dispensing action of the mechanism, and during such time as the rate of withdrawal of the strapping away from the present machine remains substantially as great as the 'rate at which the strapping is fed off of the coil, the strapping will follow a discharge path to the exit guide tube .80 generally along the path indicated by the numeral 34a in FIG. 1. This discharge path, in the immediate area of the loop at the free end .of the sensor unit 67, is schematically illustrated by the broken line representation of'the strapping in FIG. 4, it being observed that the longitudinally concave side of the strapping passes across the rod length 67b, but is, at this time, normally out of contact with the other rod length 67c which is always spaced from the rod length 67b a fixed distance and is disposed opposite the convex side of the strapping and displaced from the rod length 67b in the direction opposite the direction of the longitudinal movement of the strapping.

So long as the withdrawal of strapping from the apthe force of thebucklin'g strap itself.

paratus proceeds at a rate that is not substantially less than the rate at which the strapping is unwound fronteneaof t the coil by the driving aetion'lof; the motor 49, the strapping, withinjthe area of the'present apparatus, will continue to follow substantially the discharge path designated below the rate at which the strapping is unwound from. the coil by virtue of the driving action of the motor 40, T

the strapping in the discharge. pathwithin the apparatus bulge outwardly toward the broken line. strapping dis charge path designated by the numeral 34b in FIG. 1, this same discharge path 34b being schematically illustrated by solid line representation of the strapping in FIG. 4. As the accumulation of excess strapping in the areaiof the discharge path within the machine grows; the conj tinuing increase inthe outward buckling'of the strapping will likewise grow and will, consequently, begin to pivot the sensor unit 67 from its broken line position in FIG; 1 toward its full line position. At the same time, as the buckling condition grows, the convex .side' of the strapping in the area of the discharge path will approach closer and closer, to'the rod length 67c of the loop at the outer. end of the sensor unit. As the sensor unit in its pivotalhmovement, moves toward the full line position thereof shown in FIG., L'th ecam surface 70 on-the cam block 69 will become disengaged from' the roller 71 on the switch actuator 72, and will interrupt 1 V the electrical ,energization of the drive motor 40, thereby to interrupt the application of driving power to the coilsupporting wheel assembly. Furthermore, as the buckling grows, the convex or outerside of. thestrapping inthe area of'the discharge path' will come into forceful of the application of power to the coil-supporting wheel assembly, the inertia of the wheel assembly and the coil of strapping supported. thereon will cause the wheel as-' sembly andthe coil to coast momentarily before they 67b of the loop at the outer endof the sensor unit .67,

and simultaneously increasing the force applied by the. convex or outer side'of the strapping tothe'r'od length 670 of the loop. These forces applied by the buckled strapping upon the rod lengths 6711 and. 67c are schematically represented-by the arrows 100 and 101 in FIG.

4, and it will be .understood'that they are generated by seenthat the bulged strapping tends frictionally to 'bind forcefully between the rod lengths 67b and 670, so'that -these rod lengths exert both a braking force upon the continued movement of the strapping past the' ro d'lengths 67b and-67c, and also-a strap gripping force.

the strapping,'thereby stopping the buckling, and the gripping action afforded by the rodlengths 67b and 67c causesfull-control to be captured over the strapping-1 in the discharge path. This controloverthe-strapping? is augmented by the fact that the top' and bottom of the, loop at the outer e'nd'of thesen'sorfunit 67' -areclosed j V V by the'rodlengths 67d and 672 softhat -the.;strapping cannot, under anycircumstance, slip. upwardlyjorf 'dowm Wardly out'of the gripof therod lengthsi67b'andi67c,

Thus, it' will be loss' of control "of the "strapping; with the occasional I springing of convolutionsof strapping from the coil 34, 'isentirely overcome and avoided. The strapping is thus maintained in close and positive control, with the strap ping being firmly held in the discha'rge path and in the position represented in the drawings by the numeral 34b, until Withdrawal of further strapping 'from the presentapparatus is resumed. Upon ithe resurnption' of such char ge path 34b-between the exitguide tube 80 and the. and ahead of the guide tube '80 will start to buckle or In summary, it is to be noted that the withdrawaL the tug or pull on the'outer end of the strapping-first reduces the *buckle of the strapping in the disloop at the outer ender the sensor unit 67, and further withdrawal of strapping causes the sensor unit' to begin topivot from its full line position illustrated in FIG. 1 toward its 'b'rokenline position. This pivotation of the sensor unit'gra'duaIIy causesthegrip on the strapping to be released and again \causes the cam. surface 70 onvthe cam block 69 to engagethe wheel 71 of the switch actuator 72, thereby again closing the switch'53 and resuming the driving action exerted by the motor 40 upon the coil-supporting wheel assembly. Thus, power-driven dispensing action is resumed after having been previously interrupted, WilillOllt the operator having touched the machine or having experienced any' loss of control or tangling or damage to, the strapping. p

inside or longitudinally, concave sidejof the strapping is in contact with the rod' length 67b ofi-the loop at the outer end of the sensor unit 67 when the sensor unit is in either-of the positions thereoffshownin the drawing, and that the outer or convex sideofthe strapping engages and begins making ever increasingly forceful contact with the rod length 670 contact with the rod 'length 67c ofthe loop at the outer end of the sensor unit 67. Subsequent to the termination as the strapping begins tobuckle' outwardly'from the path 34:; toward the path designated. by the numeral 34b. These "conditions are illustrated schematically in FIG. 4 and it will there be seen that'the two' rod lengths 67b and "67b liel-in -a plane whichintersects the general plane of 1 the strappingtherebetween at "an acute angle, that angle ;the,gripping and braking action, which is generated by the buckling of thestrapping itself, is progressively and automatically increased as the buckling increases, thereby exerting greater control when greater control is needed.

'klthoughonly one specific embodiment of the present j invention has been shown in the'drawing and described tions maybe rnade therein, audit will also be understood h that the mvention'maybe employed for dispensingwire 'T' c braking actionjustreferred'to stops the further feeding of strapping from the' coil Mintothe discharge path of above for, purposes of illustration, it'will be understood by those skilledin the art that various changes'and modificaand materials other lthan'strapping; Accordingly, when the word's"strap or strapping are used in the appended claims, it is intended to mean bothstrapping and wire {and like materialaand it is intended toicover in -f the appended claims all modifications as fall within'th true i spirit andvscope of'the invention.

which are parallel and are also substantiallyparallel to the axis of the shaft 19. Y j V The result of-.thefg ripping and brakingiaction ex 'rlted.

- by the rod lengths 67b and i67c1of the loop at thefou'ter "1 end of'the' sensor uni r 67 is that; the prion-problem. of

for-supporting thetcoil for. rotation about an axis, means 7 motormeans for driving saidsupporting means n a co l unwinding direction about said axisan'd forfee'd-V ingthe strappingffrom the'coil along' a curved discharge path wherein ithe'strapping is curved in the same direction ,i'L-"In mechanisrntor dispensing strapping and the like from a coil thereof, the combination comprising, means sneassa convex, a movable sensor unit, a first strap engaging member on said sensor unit adapted to contact said concave side of said strapping in the area of said discharge path, a second strap engaging member on said sensor unit adapted to contact said convex side of said strapping, said second strap engaging member being disposed in an adjacent predetermined spaced-apart position with respect to said first strap engaging member and being displaced from said first strap engaging member in the direction opposite the direction of movement of said strapping through said discharge path, said strapping tending to bulge outwardly with respect to said discharge path and to move said strap engaging members and said sensor unit therewith when the rate of removal of said strapping along said discharge path becomes substantially less than the rate at which the strapping is unwound from the coil, the strapping in the bulged portion thereof tending to bind between said strap engaging members, whereby said strap engaging members serve to grip the bulged strapping therebetween and prevent loss of control thereof, and means responsive to the movement of said sensor unit for controlling said motor means.

2. In mechanism for dispensing strapping and the like from a coil thereof, the combination comprising, means for supporting the coil for rotation about an axis, a strap guide, means including motor means for driving said supporting means in a coil-unwinding direction about said axis and for feeding the strapping along a curved discharge path from the coil to said guide, one side of the strapping in said curved path being longitudinally concave and the other side thereof being convex, a movable sensor unit, a first strap engaging member on said sensor unit adapted to contact said concave side of said strapping in the area of said discharge path, a second strap engaging member on said sensor unit adapted to contact said convex side of said strapping, said second strap engaging member being disposed in an adjacent predetermined spaced-apart position with respect to said first strap engaging member and being displaced from said first strap engaging member in the direction opposite the direction of movement of said strapping through said discharge path, said strapping tending to bulge outwardly with respect to said discharge path and to move said strap engaging members and said sensor unit therewith when the rate of removal of said strapping along said discharge path becomes substantially less than the rate at which the strapping is unwound from the coil, the strapping in the bulged portion thereof tending to bind between said strap engaging members, whereby said strap engaging members serve to grip the bulged strapping therebetween and prevent loss of control thereof, and means responsive to the movement of said sensor unit for controlling said motor means.

3. The combination set forth in claim 2, wherein said sensor unit comprises a pivoted arm carrying said strap engaging members.

4. The combination set forth in claim 2, wherein said sensor unit comprises an arm pivotally mounted adjacent said guide and wherein said strap engaging members are on a free end portion of said arm.

5. The combination set forth in claim 2, wherein said sensor unit comprises a light weight arm pivotally mounted adjacent said guide, and where said strap engaging members comprise the opposite sides of a substantially closed loop on a free end of said arm.

6. The combination set forth in claim 5, wherein said strap engaging members are-provided with friction surfaces for gripping said strapping and for braking the longitudinal movement of said strapping.

7. In mechanism for dispensing strapping and the like from a coil thereof, the combination comprising, a rotatable Wheel assembly for supporting the coil for rotation about a substantially vertical axis, a strap guide adjacent said wheel assembly, means including an electric motor for driving said wheel assembly in a coil-unwinding direction and for feeding strapping along a curved discharge path from said coil to and through said guide, one side of the strapping in said curved path being longitudinally concave and the other side thereof being convex, a sensor arm pivotally mounted adjacent said guide and projecting in a direction generally in alignment with and adjacent said discharge path, a first strap engaging member on said sensor arm adapted to contact said concave side of said strapping in said discharge path, a second strap engaging member on said sensor arm adapted to contact said convex side of said strapping, said second strap engaging member being disposed in an adjacent predetermined spaced-apart position with respect to said first strap engaging member and being displaced from said first strap engaging member in the direction opposite the direction of movement of said strapping from said coil to said guide, said strapping tending to bulge outwardly with respect to said discharge path and thereby to move said strap engaging members and pivot said sensor arm when the rate of removal of said strapping through said guide becomes substantially less than the rate at which the strapping is unwound from the coil, the strapping in the bulged portion thereof tending to bind between said strap engaging members, whereby said strap engaging members grip the bulged strapping therebetween and prevent loss of control thereof, a switch for controlling the energization of said motor, and means connected to said sensor arm for actuating said switch in response to pivotal movement of said arm.

8. The combination set forth in claim 7, wherein said sensor arm is also pivotal upwardly away from the area of said discharge path and wherein said switch actuating means is carried to a position remote from said switch by the upward pivotal motion of said arm, thereby to remove said sensor arm from said area of said discharge path and at the same time avoid actuation of said switch.

9. The combination set forth in claim 7, wherein said rotatable wheel assembly includes a rim, said electric motor is provided with a friction wheel drivingly engaging an under surface of said rim, and said motor is pivotally mounted adjacent said friction wheel, whereby the weight of said motor causes said friction wheel constantly to bear upon said under surface of said rim despite irregularities that may exist in said rim.

10. In mechanism for dispensing strapping and the like from a coil thereof, means for supporting the coil for rotation about an axis, means including motor means for driving said supporting means in a coil-unwinding direction about said axis and for feeding the strapping along a curved discharge path, a movable sensor unit, means on said sensor unit in substantially constant contact with said strapping in said discharge path and gripping said strapping when said sensor unit is moved responsive to bulging of said strapping with respect to said discharge path, and means responsive to the movement of said sensor unit for controlling said motor means.

References Cited by the Examiner UNITED STATES PATENTS 1,147,680 7/15 Crawford.

1,864,267 6/32 Baker et al.

2,155,771 4/39 Porter 242128 2,347,552 4/44 7 Gerrard 242l05 3,061,235 10/62 Lingle 242--78.6 X

MERVIN STEIN, Primary Examiner. 

10. IN MECHANISM FOR DISPENSING STRAPPING AND THE LIKE FROM A COIL THEREOF, MEANS FOR SUPPORTING THE COIL FOR ROTATION ABOUT AN AXIS, MEANS INCLUDING MOTOR MEANS FOR DRIVING SAID SUPPORTING MEANS IN A COIL-UNWINDING DIRECTION ABOUT SAID AXIS AND FOR FEEDING THE STRAPPING ALONG A CURVED DISCHARGE PATH, A MOVABLE SENSOR UNIT, MEANS ON SAID SENSOR UNIT IN SUBSTANTIALLY CONSTANT CONTACT WITH SAID STRAPPING IN SAID DISCHARGE PATH AND GRIPPING SAID STRAPPING WHEN SAID SENSOR UNIT IS MOVED RESPONSIVE TO BULGING OF SAID STRAPPING WITH RESPECT TO SAID DISCHARGE PATH, AND MEANS RESPONSIVE TO THE MOVEMENT OF SAID SENSOR UNIT FOR CONTROLLING SAID MOTOR MEANS. 